Cooling devices including jet cooling with an intermediate mesh and methods for using the same

ABSTRACT

An assembly includes a substrate defining a base portion defining a plurality of orifices that extend through the base portion, the plurality of orifices defining a plurality of jet paths extending along and outward from the plurality of orifices, a mesh coupled to the base portion, the mesh defining a plurality of pores aligned with the plurality of jet paths, an encapsulated phase-change layer positioned on the mesh, and a heat-generating device coupled to the mesh opposite the base portion, the heat-generating device defining a bottom surface that is oriented transverse to the plurality of jet paths.

FIELD

The present specification generally relates to apparatuses for coolingheat-generating devices and, more specifically, to cooling devicesutilizing jet cooling and including an intermediate mesh.

TECHNICAL BACKGROUND

Cooling devices may be coupled to a heat-generating device, such as apower electronics device, to remove heat and lower the operatingtemperature of the heat-generating device. Cooling fluid may be used toreceive heat generated by the heat-generating device by convectiveand/or conductive thermal transfer, and may remove such heat from theheat-generating device. For example, a jet of cooling fluid may bedirected such that it impinges a surface of the heat-generating device.

However, as some heat-generating devices are designed to operate atincreased power levels and generate increased corresponding heat flux,for example due to the demands of newly developed electrical systems,conventional cooling devices are unable to adequately remove the heatflux to effectively lower the operating temperature of theheat-generating devices to acceptable temperature levels.

Accordingly, a need exists for alternative cooling devices for coolingheat-generating devices.

SUMMARY

In one embodiment, a cooling assembly includes a substrate defining abase portion defining a plurality of orifices that extend through thebase portion, the plurality of orifices defining a plurality of jetpaths extending along and outward from the plurality of orifices, a meshcoupled to the base portion, the mesh defining a plurality of poresaligned with the plurality of jet paths, an encapsulated phase-changelayer positioned on the mesh, and a heat-generating device coupled tothe mesh opposite the base portion, the heat-generating device defininga bottom surface that is oriented transverse to the plurality of jetpaths.

In another embodiment, a power electronics assembly includes a substrateincluding a base portion defining a plurality of orifices that extendthrough the base portion, the plurality of orifices defining a pluralityof jet paths extending along and outward from the plurality of orifices,a mesh coupled to the base portion, the mesh defining a plurality ofpores aligned with the plurality of jet paths, an encapsulatedphase-change layer positioned within the mesh, and a power electronicsdevice electrically coupled to the substrate through the mesh.

In yet another embodiment, a method for cooling a heat-generatingdevice, the method includes passing a cooling fluid along a jet pathextending along an orifice extending through a substrate, passing thecooling fluid through a pore of mesh, where the pore is aligned with theorifice, impinging the cooling fluid on a heat-generating devicepositioned opposite the orifice and thermally coupled to theheat-generating device, heating the mesh, and changing a matter phase ofan encapsulated phase-change material of a phase-change layer positionedon the mesh.

Additional features of the cooling devices and methods for coolingheat-generating devices described herein will be set forth in thedetailed description which follows, and in part will be readily apparentto those skilled in the art from that description or recognized bypracticing the embodiments described herein, including the detaileddescription which follows, the claims, as well as the appended drawings.

It is to be understood that both the foregoing general description andthe following detailed description describe various embodiments and areintended to provide an overview or framework for understanding thenature and character of the claimed subject matter. The accompanyingdrawings are included to provide a further understanding of the variousembodiments, and are incorporated into and constitute a part of thisspecification. The drawings illustrate the various embodiments describedherein, and together with the description serve to explain theprinciples and operations of the claimed subject matter.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 schematically depicts a perspective view of a cooling assembly,according to one or more embodiments shown and described herein;

FIG. 2 schematically depicts an exploded view of the cooling assembly ofFIG. 1, according to one or more embodiments shown and described herein;

FIG. 3A schematically depicts a section view of the cooling assembly ofFIG. 1 along section 3A-3A of FIG. 1, according to one or moreembodiments shown and described herein;

FIG. 3B schematically depicts an enlarged view of a mesh of the coolingassembly of FIG. 3A, according to one or more embodiments shown anddescribed herein;

FIG. 4 schematically depicts a perspective view of a substrate and aheat-generating device of the cooling assembly of FIG. 1, according toone or more embodiments shown and described herein;

FIG. 5 schematically depicts a section view of the cooling assembly ofFIG. 1 along section 5-5 of FIG. 1, according to one or more embodimentsshown and described herein;

FIG. 6 schematically depicts a section view of the cooling assembly ofFIG. 1 along section 6-6 of FIG. 1, according to one or more embodimentsshown and described herein; and

FIG. 7 schematically depicts a section view of another cooling assembly,according to one or more embodiments shown and described herein.

DETAILED DESCRIPTION

Reference will now be made in detail to embodiments of cooling devicesand methods of operating the same, examples of which are illustrated inthe accompanying drawings. Whenever possible, the same referencenumerals will be used throughout the drawings to refer to the same orlike parts.

Embodiments described herein are directed to heat-generating devices andmethods for cooling the heat-generating devices. The heat-generatingdevices may include, as one non-limiting example, power electronicsmodules including a power electronics device. The power electronicsdevice generally generates heat during operation that should bedissipated. Cooling fluid may be utilized to dissipate the heat byimpinging the cooling fluid on the heat-generating device, and it isgenerally desirable to maximize the heat dissipated with the coolingfluid, for example by optimizing the flow characteristics of the coolingfluid (e.g., the flow velocity, the positioning of the flow, etc.).

Embodiments described herein are directed to cooling assembliesincluding a heat-generating device and a substrate coupled to theheat-generating device. The substrate generally includes a base portiondefining a plurality of orifices extending through the base portion anda plurality of jet paths extending along and outward from the pluralityof orifices. A mesh is coupled to the substrate, the mesh including aplurality of pores that are aligned with the plurality of orifices andthe plurality of jet paths. The heat-generating device is coupled to themesh and defines a bottom surface that is oriented transverse to theplurality of jet paths. Cooling fluid may be passed through theplurality of jet paths, through the plurality of pores of the mesh, andimpinge on the bottom surface of the heat-generating device to removethermal energy generated by the heat-generating device.

The plurality of pores of the mesh may change the flow pattern and/orthe flow velocity of the cooling fluid to optimize the dissipation ofthermal energy as the cooling fluid impinges on the heat-generatingdevice. Additionally, in embodiments described herein, an encapsulatedphase-change layer is positioned on the mesh and/or the substrate, andthe phase-change layer may further dissipate heat from theheat-generating device, which may further assist in maintaining theheat-generating device at an acceptable operating temperature. Variousembodiments of power electronics modules and methods for operating thesame will be described herein with specific reference to the appendeddrawings.

As used herein, the term “longitudinal direction” refers to theforward-rearward direction of the cooling assembly (i.e., in the+/−X-direction as depicted). The term “lateral direction” refers to thecross-direction of the cooling assembly (i.e., in the +/−Y-direction asdepicted), and is transverse to the longitudinal direction. The term“vertical direction” refers to the upward-downward direction of thecooling assembly (i.e., in the +/−Z-direction as depicted), and istransverse to the lateral and the longitudinal directions.

Referring initially to FIG. 1, a perspective view of a cooling assembly100 is schematically depicted. The cooling assembly 100 generallyincludes a heat-generating device 140 and a housing 150 surrounding atleast a portion of the heat-generating device 140. The housing 150 maybe formed from a thermally conductive material that receives anddissipates heat from the heat-generating device 140. For example andwithout limitation, the housing 150 may be formed from aluminum, silver,gold, copper, or the like. While the heat-generating device 140 and thehousing 150 depicted in FIG. 1 generally define rectangular shapes, itshould be understood that the heat-generating device 140 and the housing150 may include any suitable shape.

In embodiments, the heat-generating device 140 may include anelectronics device. In some embodiments, the heat-generating device 140may include a power electronics device that controls and/or convertselectrical power. For example, the heat-generating device 140 may be oneor more semiconductor devices that may include, without limitation, aninsulated-gate bipolar transistor (IGBT), a reverse conducting IGBT(RC-IGBT), a metal-oxide-semiconductor field-effect transistor (MOSFET),a power MOSFET, diodes, transistors, and/or combinations thereof (e.g.,power cards). In some embodiments, the heat-generating device 140 mayinclude a wide-bandgap semiconductor, and may be formed from a suitablematerial, for example and without limitation, diamond, silicon carbide(SiC), or the like. In embodiments, in which the heat-generating device140 includes an electronics device, the heat-generating device 140 maybe electrically coupled to electrodes such as a gate electrode via awired or bonded connection.

In embodiments in which the heat-generating device 140 includes a powerelectronics device, the power electronics device may be used in avehicular electrical system, for example as part of an inverter systemin an electric or hybrid-electric vehicle. In vehicular applications,the heat-generating device 140 may generate significant heat flux thatshould be dissipated to maintain the heat-generating device 140 at asuitable operating temperature. While the heat-generating devices 140described herein are generally described as being power electronicsdevices utilized in a vehicular electrical system, it should beunderstood that the heat-generating devices 140 described herein mayinclude devices suitable for use in any other application.

Referring to FIG. 2, an exploded perspective view of the coolingassembly 100 is schematically depicted. The heat-generating device 140is spaced apart from a substrate 110 in the vertical direction, and amesh 160 is positioned between the heat-generating device 140 and thesubstrate 110 in the vertical direction. In some embodiments, thecooling assembly 100 includes a plurality of posts 130 positionedbetween the substrate 110 and the heat-generating device 140 in thevertical direction. In the embodiment depicted in FIG. 2, the coolingassembly 100 includes a plurality of posts 130 positioned between themesh 160 and the heat-generating device 140, and a plurality of posts130 positioned between the mesh 160 and the substrate 110 in thevertical direction. The plurality of posts 130 generally space thesubstrate 110 apart from the heat-generating device 140 in the verticaldirection, which may affect an impingement distance evaluated betweenthe substrate 110 and the heat-generating device 140, as described ingreater detail herein.

Referring to FIG. 3A, a section view of the cooling assembly 100 alongsection 3A-3A of FIG. 1 is schematically depicted. The heat-generatingdevice 140 generally defines an upper surface 146 oriented to faceupwards in the vertical direction and a bottom surface 148 that ispositioned opposite the upper surface 146 and that is oriented to facedownwards in the vertical direction.

In some embodiments, the cooling assembly 100 optionally includes anintermediate layer 180 positioned between the substrate 110 and theheat-generating device 140 in the vertical direction, and the substrate110 is coupled to the heat-generating device 140 through theintermediate layer 180. More particularly, the intermediate layer 180 isengaged with the bottom surface 148 of the heat-generating device 140,and the substrate 110 is coupled to the heat-generating device 140through the intermediate layer 180. In the embodiment depicted in FIG.3A, the intermediate layer 180 may generally include a solder plate thatextends across the bottom surface 148 of the heat-generating device 140,and to which individual posts 131 of the plurality of posts 130 may becoupled. In other embodiments, the intermediate layer 180 may includesolder solely positioned at discrete positions between the plurality ofposts 130 and the heat-generating device 140 to couple the plurality ofposts 130 to the heat-generating device 140. In these embodiments, thesolder does not generally extend between individual posts 131 of theplurality of posts 130 in the lateral and/or the longitudinaldirections.

In some embodiments, the intermediate layer 180 may include anencapsulated phase-change material. For example, the intermediate layer180 may include a phase-change material, such as and without limitation,indium, hydrated salt, molten salt, metal alloys, paraffin, carboxylicacid, ester, polyol, organic matter, crystal hydrated salt, or anysuitable combination thereof. The phase-change material may beencapsulated within the intermediate layer 180 by any suitableencapsulating material, for example by platinum, aluminium, or the likewhich may be deposited through any suitable process, such as atomiclayer deposition (ALD), chemical vapor deposition, or the like. Thephase-change material may be selected to transition between one phase(e.g., a solid state) to another phase (e.g., a liquid state) at oraround the operating temperature of the heat-generating device 140.Without being bound by theory, the re-arrangement of the structure of amaterial as the material changes to a higher phase (e.g., from a solidstate to a liquid state) requires thermal energy, such that the materialabsorbs thermal energy from its surroundings when changing to the higherphase. As such, by including an intermediate layer 180 including anencapsulated phase-change material, cooling assemblies 100 including theintermediate layer 180 with the encapsulated phase-change material mayabsorb more thermal energy from the heat-generating device 140 ascompared to cooling assemblies that do not include an intermediate layerwith the encapsulated phase-change material.

In embodiments, the substrate 110 generally includes a base portion 114that defines an inlet face 118 that is oriented to face downward in thevertical direction, and an outlet face 116 positioned opposite the inletface 118 and oriented to face upward in the vertical direction. The baseportion 114 further defines a plurality of orifices 120 extendingthrough the base portion 114 between the inlet face 118 and the outletface 116. The plurality of orifices 120 includes individual orifices 122that collectively define a plurality of jet paths 124 extending alongand outward from the plurality of orifices 120. In embodiments, a spanof each of the individual orifices 122 of the plurality of orifices 120generally defines a span of each of the plurality of jet paths 124. Forexample, in some embodiments in which the individual orifices 122 arecircular, a diameter of each of the individual orifices 122 generallydefines a diameter of each of the plurality of jet paths 124. Theplurality of jet paths 124 extends in the vertical direction such thatthe plurality of jet paths 124 is transverse to the bottom surface 148of the heat-generating device 140. In some embodiments, the bottomsurface 148 of the heat-generating device 140 may form a target surfacefor a cooling fluid. For example, a cooling fluid may be passed throughthe plurality of orifices 120 along the plurality of jet paths 124 andimpinge on bottom surface 148 of the heat-generating device 140 or theintermediate layer 180 positioned on the bottom surface 148 of theheat-generating device 140, as described in greater detail herein. Insome embodiments, the substrate 110 is formed of an electrically andthermally conductive material, such as copper, a copper alloy, or thelike.

Referring to FIG. 3B an enlarged view of the mesh 160 is schematicallydepicted. In embodiments, the mesh 160 defines a plurality of pores 162extending through the mesh 160 in the vertical direction. Individualpores 163 of the plurality of pores 162 are aligned with the individualjet paths 125 and the individual orifices 122, such that a cooling fluidpassed along the plurality of jet paths 124 passes through the pluralityof pores 162 of the mesh 160.

In some embodiments, a span of each of the pores 163 of the plurality ofpores 162 is different than the span of the individual orifices 122 ofthe plurality of orifices 120. For example, in some embodiments, thespan of each of the pores 163 of the plurality of pores 162 may besmaller than the span of each of the individual orifices 122 of theplurality of orifices 120. In these embodiments, the span of each of thepores 163 of the plurality of pores 162 may be less than the span ofeach of the jet paths 125 of the plurality of jet paths 124 positioneddownward from the mesh 160, since the span of each of the jet paths 125is generally defined by the span of the individual orifices 122. In thisway, the plurality of pores 162 of the mesh 160 may restrict theplurality of jet paths 124, which may affect a velocity of cooling fluidpassing upward through the plurality of pores 162 toward theheat-generating device 140, for example as a result of the Bernoullieffect. Furthermore, the span of the plurality of pores 162 of the mesh160 may be selected to assist in focusing cooling fluid passing throughthe plurality of jet paths 124, which may further assist in dissipatingheat from the heat-generating device 140. While the plurality of pores162 and the plurality of orifices 120 are generally depicted asincluding a circular shape where the span of the plurality of pores 162and the plurality of orifices 120 generally defines a diameter, in otherembodiments, the plurality of pores 162 and/or the plurality of orifices120 may include any suitable geometry, for example and withoutlimitation, a rectangular shape, a square shape, or the like. In theembodiment depicted in FIG. 3B, the mesh 160 is coupled to theheat-generating device 140 through posts 131 of the plurality of posts130, and the mesh 160 is coupled to the base portion 114 of thesubstrate 110 through posts 131 of the plurality of posts 130. The posts131 may generally space the mesh 160 apart from the base portion 114 ofthe substrate 110 and/or the heat-generating device 140 in the verticaldirection. By spacing the mesh 160 apart from the base portion 114 ofthe substrate 110, the posts 131 may affect the flow characteristics(e.g., flow velocity and/or flow path) of cooling fluid being passedalong the plurality of jet paths 124. In embodiments, the posts 131 ofthe plurality of posts 130 may electrically couple and/or thermallycouple the mesh 160 to the heat-generating device 140 and the baseportion 114 of the substrate 110, and the plurality of posts 130 maygenerally be formed of an electrically and thermally conductivematerial, for example and without limitation, copper, a copper alloy,solder, or the like, and may be deposited in any suitable manner, forexample and without limitation an additive manufacturing process such astransient liquid phase solder deposition or the like. In someembodiments, the mesh 160 may be formed of an electrically conductivematerial, such that the heat-generating device 140 is electricallycoupled and/or thermally coupled to the base portion 114 of thesubstrate 110 through the mesh 160. For example, in some embodiments,the mesh 160 may be formed of an electrically and thermally conductivematerial, such as copper, a copper alloy, solder, or the like.

Without being bound by theory, the size and shape of posts 131 of theplurality of posts 130 and the mesh 160 influences the transmission ofelectrical current between the base portion 114 and the heat-generatingdevice 140 through the plurality of posts 130 and the mesh 160, as wellas the transmission of thermal energy through the plurality of posts 130and the mesh 160, for example to a cooling fluid in contact with theplurality of posts 130 and the mesh 160. In one embodiment, each of theposts 131 define a cross-sectional area evaluated in a plane extendingin the lateral and the longitudinal directions that is between 0.25millimeters squared and 0.75 millimeters squared. In another embodiment,each of the posts 131 define a cross-sectional area evaluated in a planeextending in the lateral and the longitudinal directions that is that isabout 0.5 millimeters squared. The specific geometry and cross-sectionalarea of each of the posts 131 of the plurality of posts 130 and the mesh160 may be selected to achieve desired cooling and/or electricaltransmission properties.

In embodiments, the mesh 160 includes a planar portion 166 thatgenerally defines the plurality of pores 162, and a plurality ofengagement portions 164 extending outward from the planar portion 166.In the embodiment depicted in FIG. 3B, the mesh 160 includes a pluralityof engagement portions 164 extending upward from the planar portion 166in the vertical direction, and a plurality of engagement portions 164extending downward from the planar portion 166 in the verticaldirection. The plurality of engagement portions 164 generally extendoutward from the planar portion 166 in the vertical direction, therebyspacing the planar portion 166 apart from heat-generating device 140 andthe base portion 114 of the substrate 110. While in the embodimentdepicted in FIG. 3B, the mesh 160 includes engagement portions 164extending upward from the planar portion 166 and engagement portions 164extending downward from the planar portion 166, in other embodiments,the mesh 160 may include only engagement portions 164 extending upwardfrom the planar portion 160 or only engagement portions 164 extendingdownward from the planar portion 160, as described in greater detailherein. In other embodiments, the mesh 160 may include only the planarportion 166 and may be formed without the engagement portions 164. Theinclusion or omission of the engagement portions 164 and the positioningof the engagement portions 164 (i.e., extending upward and/or downwardfrom the planar portion 166) may impact the flow characteristics ofcooling fluid impinged on the heat-generating device 140 and/or theintermediate layer 180.

For example, an impingement distance (i.e., a distance evaluated betweenthe plurality of orifices 120 and the bottom surface 148 of theheat-generating device 140 or the intermediate layer 180) influences theamount of thermal energy that may be absorbed from the heat-generatingdevice 140 when cooling fluid passing through the plurality of orifices120 is impinged against the heat-generating device 140 and/or theintermediate layer 180. As shown in FIG. 3B, the impingement distance isdependent upon the height of the plurality of posts 130 and the heightof the engagement portions 164 of the mesh 160 evaluated in the verticaldirection. As such, the height of the plurality of posts 130 and theheight of the mesh 160 may be selected to achieve a desired impingementdistance. In some embodiments, the height of the plurality of posts 130and the mesh 160 evaluated in the vertical direction is between 100micrometers and 300 micrometers, inclusive of the endpoints. In oneembodiment, the height of the plurality of posts 130 and the mesh 160evaluated in the vertical direction is about 200 micrometers.

In some embodiments, an encapsulated phase-change layer 190 may bepositioned on the mesh 160, the substrate 110, and/or the posts 131 ofthe plurality of posts 130. In some embodiments, the encapsulatedphase-change layer 190 may be positioned within the mesh 160, forming atleast a portion of the mesh 160. The encapsulated phase-change layer 190may be in communication with the intermediate layer 180, for example, inembodiments in which the intermediate layer 180 includes a phase-changematerial. In other embodiments, for example in embodiments in which theintermediate layer 180 does not include a phase-change material, theencapsulated phase-change layer 190 positioned on the mesh 160, thesubstrate 110, and/or the posts 131 may be separate and distinct fromthe intermediate layer 180.

Similar to the phase-change material of the intermediate layer 180,phase-change material within the encapsulated phase-change layer 190 mayinclude, for example and without limitation, indium, hydrated salt,molten salt, metal alloys, paraffin, carboxylic acid, ester, polyol,organic matter, crystal hydrated salt, or any suitable combinationthereof. Phase-change material within the encapsulated phase-changelayer 190 may be encapsulated by any suitable encapsulating material,for example, by platinum or aluminium that may be deposited through anysuitable process, such as ALD, chemical vapor deposition, or the like.Phase-change material within the encapsulated phase-change layer 190 maybe selected to transition between one phase (e.g. a solid state) toanother phase (e.g. a liquid state) at or around the operatingtemperature of the heat-generating device 140. In operation, theheat-generating device 140 transmits thermal energy to the posts 131 andthe mesh 160, for example through the intermediate layer 180 and/orthrough contact between the posts 131 and the heat-generating device140. The phase-change layer 190 may absorb thermal energy from the posts131 and the mesh 160 as phase-change material within the phase-changelayer 190 transitions between phases. As such, cooling assemblies 100including the encapsulated phase-change layer 190 positioned on the mesh160, the substrate 110, and/or the plurality of posts 130 may absorbmore thermal energy from the heat-generating device 140, as compared toconfigurations that do not include the with the encapsulatedphase-change layer 190.

Referring collectively to FIGS. 3A, 3B, and 4, the section views of thecooling assembly 100 and an enlarged side view of the cooling assembly100 is depicted with the housing 150 (FIG. 1) removed. In operation, theheat-generating device 140 generates heat that should be dissipated tomaintain the heat-generating device 140 within an acceptable temperaturerange. To dissipate heat generated by the heat-generating device 140, acooling fluid is passed between the inlet face 118 and the outlet face116 through individual orifices 122 of the plurality of orifices 120 andimpinges on the heat-generating device 140 and/or the intermediate layer180. In other embodiments, such as embodiments that do not include theintermediate layer 180 and/or in which the intermediate layer 180 doesnot extend between the posts 131 of the plurality of posts 130, thecooling fluid may directly impinge on the bottom surface 148 of theheat-generating device 140. The cooling fluid may be driven through theplurality of orifices 120, for example by a pump or the like.

Subsequent to impinging on the heat-generating device 140, the coolingfluid flows outward towards an outer perimeter of the substrate 110.More particularly, the cooling fluid generally passes through coolingfluid passageways 170 positioned between the posts 131 of the pluralityof posts 130 and/or between the engagement portions 164 of the mesh 160,toward the outer perimeter of the substrate 110.

Referring again to FIG. 3A, the housing 150 may generally encapsulatethe substrate 110, such that the cooling fluid passageways 170 (FIG. 4)are contained within the housing 150. In embodiments, the housing 150and the substrate 110 and the housing 150 define an outlet channel 152positioned between the housing 150 and the outer perimeter of thesubstrate 110 and in fluid communication with the cooling fluidpassageways 170 (FIG. 4). As the cooling fluid flows outward in thelateral and the longitudinal directions along the cooling fluidpassageways 170 (FIG. 4) to the outer perimeter of the substrate 110,the cooling fluid may flow downward through the outlet channel 152. Thecooling fluid may subsequently be cooled, and then passed through theplurality of orifices 120 to impinge on the heat-generating device 140again, thereby repeating the process.

In some embodiments, the cooling fluid may be formed from anelectrically-conductive fluid, such as an ethylene glycol mixture,water, or the like. In these embodiments, the substrate 110, theheat-generating device 140, the plurality of posts 130, and/or the mesh160 may be electrically insulated from the cooling fluid, for example byan electrically insulating layer 192 positioned on surfaces of thesubstrate 110, the heat-generating device 140, the plurality of posts130, and/or the mesh 160, as shown in FIG. 3B. Theelectrically-insulating layer 192 is formed from anelectrically-insulating material that inhibits the transmission ofelectrical current through the electrically-insulating layer 192, suchas and without limitation, aluminum oxide, phosphate, parylene, or thelike. In embodiments, the electrically-insulating layer 192 may have athickness of less than 1 micrometer and may be deposited on thesubstrate 110, the heat-generating device 140, the plurality of posts130, and/or the mesh 160 through a suitable deposition process, such asatomic layer deposition, chemical vapor deposition, or the like. Whilethe embodiment depicted in FIG. 3B shows the electrically-insulatinglayer 192 positioned over the encapsulated phase-change layer 190 andthe intermediate layer 180, in other embodiments, theelectrically-insulating layer 192 may be positioned beneath theencapsulated phase-change layer 190 and the intermediate layer 180, suchthat the electrically-insulating layer 192 is positioned between theencapsulated phase-change layer 190 and/or the intermediate layer 180and the substrate 110, the heat-generating device 140, the plurality ofposts 130, and/or the mesh 160. In other embodiments, dielectric coolingfluid may be utilized.

Referring to FIG. 5, another cross-section of the cooling assembly 100along section 5-5 of FIG. 1 is schematically depicted. Similar to theembodiment described above and depicted in FIGS. 3A and 3B, the coolingassembly 100 includes the heat-generating device 140, the plurality ofposts 130, the mesh 160, and the substrate 110. The cooling assembly 100may further include the encapsulated phase-change layer 190 (FIG. 3B)positioned on the mesh 160, the substrate 110, and/or on the pluralityof posts 130. However, in the embodiment depicted in FIG. 5, the mesh160 includes engagement portions 164 extending only upward from theplanar portion 166 of the mesh 160. By only including engagementportions 164 that extend upward from the planar portion 166 of the mesh160, the mesh 160 may be positioned closer to the base portion 114 ofthe substrate 110 in the vertical direction, as compared to theembodiment described above and depicted in FIGS. 3A and 3B. Furthermore,by only including engagement portions 164 that extend upward from theplanar portion 166 of the mesh 160, the distance between the baseportion 114 of the substrate 110 to the heat-generating device 140 maybe reduced, thereby reducing the impingement distance. As noted above,flow characteristics (e.g., flow velocity) of cooling fluid passingalong the plurality of jet paths 124 and impinging on the bottom surface148 of the heat-generating device 140 and/or the intermediate layer 180may be tuned to achieve desired cooling properties by changing thedistance between the mesh 160 and the base portion 114 of the substrate110 and/or by changing the distance between the base portion 114 of thesubstrate 110 and the bottom surface 148 of the heat-generating device140.

Referring to FIG. 6, another cross-section of the cooling assembly 100along section 6-6 of FIG. 1 is schematically depicted. Similar to theembodiment described above and depicted in FIGS. 3A and 3B, the coolingassembly 100 includes the heat-generating device 140, the plurality ofposts 130, the mesh 160, and the substrate 110. The cooling assembly 100may further include the encapsulated phase-change layer 190 (FIG. 3B)positioned on the mesh 160, the substrate 110, and/or on the pluralityof posts 130. However, in the embodiment depicted in FIG. 6, the mesh160 only includes engagement portions 164 extending upward from theplanar portion 166 of the mesh 160 and planar portion 166 of the mesh160 is positioned adjacent to and is in contact with the outlet face 116of the base portion 114 of the substrate 110.

By positioning the planar portion 166 of mesh 160 adjacent to and incontact with the outlet face 116 of the base portion 114 of thesubstrate 110, the impingement distance between the base portion 114 ofthe substrate 110 and the bottom surface 148 of the heat-generatingdevice 140 and/or the intermediate layer 180 may be reduced as comparedto configurations in which the mesh 160 is spaced apart from thesubstrate 110. As noted above, the flow characteristics (e.g., flowvelocity, etc.) of a cooling fluid passing along the plurality of jetpaths 124 and impinging on the bottom surface 148 of the heat-generatingdevice 140 and/or the intermediate layer 180 may be tuned to achievedesired cooling properties by changing the distance between the mesh 160and the base portion 114 of the substrate 110 and/or by changing thedistance between the base portion 114 of the substrate 110 and thebottom surface 148 of the heat-generating device 140. By minimizing theimpingement distance between the base portion 114 of the substrate 110and the bottom surface 148 of the heat-generating device 140, a velocityof the cooling fluid passing along the plurality of jet paths 124 may bemaximized, thereby increasing the amount of thermal energy that may bedissipated from the heat-generating device 140.

Referring now to FIG. 7, a section view of another cooling assembly 200is schematically depicted. Like the embodiment described above anddepicted in FIG. 3A, the cooling assembly 200 includes a heat-generatingdevice 240 defining an upper surface 246 and a bottom surface 248positioned opposite the upper surface 246. The cooling assembly 200further includes the substrate 210 coupled to the bottom surface 248 ofthe heat-generating device 240 through the mesh 260 and/or through theposts 231 of the plurality of posts 230. In embodiments, the coolingassembly 200 may further include the phase-change layer 190 (FIG. 3B)positioned on the plurality of posts 230, the mesh 260, and/or thesubstrate 210.

However, in the embodiment depicted in FIG. 7, the substrate 210 is afirst substrate 210, and the cooling assembly 200 further includes asecond substrate 210′ and a second mesh 260′ electrically coupled and/orthermally coupled to the upper surface 246 of the heat-generating device240 through a plurality of posts 230′. The first and the secondsubstrates 210, 210′ are substantially the same, and each include thebase portion 214, 214′, respectively, the base portions 214, 214′defining the plurality of orifices 220, 220′ extending through the baseportions 214, 214′, respectively. The orifices 222, 222′ of theplurality of orifices 220, 220′ each define the plurality of jet paths224, 224′, respectively extending along and outward from the orifices222, 222′. The plurality of jet paths 224, 224′ pass through the meshes260, 260′, respectively, and the mesh 260′, the plurality of posts 230′,and/or the substrate 210′ may include the phase-change layer 190 (FIG.3B).

In the embodiment depicted in FIG. 7, the cooling assembly 200optionally further includes an intermediate layer 280′ positionedbetween posts 231′ and the upper surface 246 of the heat-generatingdevice 240. In embodiments, in which the heat-generating device 240includes an electronics device, the heat-generating device 240 may beelectrically coupled to electrodes such as a gate electrode via a wiredor bonded connection.

Cooling fluid, as described above, may be passed through the orifices222 of the first substrate 210 and impinge on the intermediate layer 280and/or the bottom surface 248 of the heat-generating device 240.However, in the embodiment depicted in FIG. 7, cooling fluid may also bepassed through the orifices 222′ of the second substrate 210′ andimpinge on the intermediate layer 280′ and/or the upper surface 246 ofthe heat-generating device 240. In this way, cooling fluid may beimpinged on both the upper surface 246 and the bottom surface 248, ofthe heat-generating device 240, which may increase the amount of thermalenergy that may be transferred from the heat-generating device 240 tothe cooling fluid. Furthermore, in embodiments in which both theintermediate layers 280, 280′ include a phase-change material, the pairof intermediate layers 280, 280′ may absorb more thermal energy from theheat-generating device 240, as compared to configurations that includeonly a single intermediate layer. Furthermore, in embodiments thatincludes phase-change layers 190 (FIG. 3B) positioned on both of themeshes 260, 260′, both of the posts 231, 231′, and or both of thesubstrates 210, 210′, the phase change layers 190 may absorb morethermal energy from the heat-generating device 240, as compared toconfigurations that include a single phase change layer.

In some embodiments, the cooling assembly 200 may further include asecond housing 250′ that at least partially encapsulates the secondelectrically-conductive substrate 212′. The housing 250 and the secondhousing 250′ may both define the outlet channels 252, 252′,respectively, through which cooling fluid may pass after impinging onthe heat-generating device 240, as described above.

Accordingly, it should now be understood that embodiments describedherein are directed to cooling assemblies including a heat-generatingdevice and a substrate coupled to the heat-generating device. Thesubstrate generally includes a base portion defining a plurality oforifices extending through the base portion and a plurality of jet pathsextending along and outward from the plurality of orifices. A mesh iscoupled to the substrate, the mesh including a plurality of pores thatare aligned with the plurality of orifices and the plurality of jetpaths. The heat-generating device is coupled to the mesh and defines abottom surface that is oriented transverse to the plurality of jetpaths. Cooling fluid may be passed through the plurality of jet paths,through the plurality of pores of the mesh, and impinge on the bottomsurface of the heat-generating device to remove thermal energy generatedby the heat-generating device.

The plurality of pores of the mesh may change the flow pattern and/orthe flow velocity of the cooling fluid to optimize the dissipation ofthermal energy as the cooling fluid impinges on the heat-generatingdevice. Additionally, in embodiments described herein, an encapsulatedphase-change layer is positioned on the mesh and/or the substrate, andthe phase-change layer may further dissipate heat from theheat-generating device, which may further assist in maintaining theheat-generating device at an acceptable operating temperature.

It will be apparent to those skilled in the art that variousmodifications and variations can be made to the embodiments describedherein without departing from the spirit and scope of the claimedsubject matter. Thus it is intended that the specification cover themodifications and variations of the various embodiments described hereinprovided such modification and variations come within the scope of theappended claims and their equivalents.

What is claimed is:
 1. An assembly comprising: a substrate comprising a base portion defining a plurality of orifices that extend through the base portion, the plurality of orifices defining a plurality of jet paths extending along and outward from the plurality of orifices; a mesh coupled to the base portion, the mesh defining a plurality of pores aligned with the plurality of jet paths; an encapsulated phase-change layer positioned on the mesh; and a heat-generating device coupled to the mesh opposite the base portion, the heat-generating device defining a bottom surface that is oriented transverse to the plurality of jet paths.
 2. The assembly of claim 1, wherein a span of each orifice of the plurality of orifices of the base portion is different than a span of each of the pores of the plurality of pores of the mesh.
 3. The assembly of claim 1, wherein the mesh is spaced apart from the base portion in a vertical direction extending between the base portion and the heat-generating device.
 4. The assembly of claim 1, wherein the mesh comprises a planar portion defining the plurality of pores, and wherein the planar portion of the mesh is adjacent to and in contact with an outlet face of the base portion of the substrate.
 5. The assembly of claim 1, further comprising a plurality of posts positioned between the base portion and the mesh in a vertical direction extending between the base portion and the heat-generating device.
 6. The assembly of claim 5, wherein the encapsulated phase-change layer is positioned on the plurality of posts.
 7. The assembly of claim 1, further comprising a plurality of posts positioned between the mesh and the heat-generating device in a vertical direction extending between the base portion and the heat-generating device.
 8. The assembly of claim 1, wherein the mesh comprises a planar portion defining the plurality of pores, and a plurality of engagement portions extending outward from the planar portion in a vertical direction extending between the substrate and the heat-generating device.
 9. An electronics assembly comprising: a substrate comprising a base portion defining a plurality of orifices that extend through the base portion, the plurality of orifices defining a plurality of jet paths extending along and outward from the plurality of orifices; a mesh coupled to the base portion, the mesh defining a plurality of pores aligned with the plurality of jet paths; an encapsulated phase-change layer positioned within the mesh; and a power electronics device electrically coupled to the substrate through the mesh.
 10. The electronics assembly of claim 9, wherein the power electronics device defines a bottom surface that is oriented transverse to and intersects the plurality of jet paths.
 11. The electronics assembly of claim 9, wherein a span of each orifice of the plurality of orifices of the base portion is different than a span of each pore of the plurality of pores of the mesh.
 12. The electronics assembly of claim 9, wherein the mesh is spaced apart from the base portion in a vertical direction extending between the base portion and the power electronics device.
 13. The electronics assembly of claim 9, wherein the mesh comprises a planar portion defining the plurality of pores, and wherein the planar portion of the mesh is adjacent to and in contact with an outlet face of the base portion of the substrate.
 14. The electronics assembly of claim 9, further comprising a plurality of posts positioned between the base portion and the mesh in a vertical direction extending between the base portion and the power electronics device and electrically coupling the mesh to the power electronics device.
 15. The electronics assembly of claim 14, wherein the encapsulated phase-change layer is positioned on the plurality of posts.
 16. The electronics assembly of claim 9, further comprising an electrically insulating layer positioned on the plurality of posts.
 17. A method for cooling a heat-generating device, the method comprising: passing a cooling fluid along a jet path extending along an orifice extending through a substrate; passing the cooling fluid through a pore of mesh, wherein the pore is aligned with the orifice; impinging the cooling fluid on a heat-generating device positioned opposite the orifice and thermally coupled to the heat-generating device; heating the mesh; and changing a matter phase of an encapsulated phase-change material of a phase-change layer positioned on the mesh.
 18. The method of claim 17, wherein impinging the cooling fluid on the heat-generating device comprises impinging the cooling fluid directly on the heat-generating device.
 19. The method of claim 17, wherein impinging the cooling fluid on the heat-generating device comprises impinging the cooling fluid on an intermediate layer positioned between the substrate and the heat-generating device.
 20. The method of claim 17, further comprising changing a phase of a phase-change material of an intermediate layer positioned on a bottom surface of the heat-generating device. 